Abstract: The invention relates to a method and to apparatus for liquefying fuels for compression ignition engines and for heating installations, with the apparatus being designed to prevent filters becoming clogged with paraffin crystals and also to unclog such filters by projecting streamlines of very hot fuel (up to 70.degree. C.) thereon. The apparatus comprises one or more electrical heater resistances (18) of the extra flat circuit type formed on an electrically-insulating support (17) and then coated with an electrically-insulating coating, said resistances being placed in one or more chambers (1) which are of small volume relative to the volume of the filter and which are situated immediately upstream from the filter elements. The apparatus is such that the fuel follows an approximately U-shaped path around the heater element. An electrical temperature sensor (19) is immersed in the flow of fuel. This sensor is a low current sensor and its resistance varies as a function of temperature.

Abstract: The aqueous substance, for example sea water, is boiled, the steam produced is fed under pressure into a turbo-alternator turbine producing electricity, the residual steam is reduced into soft water and the residue of evaporation, for example sea salt, is recovered as a by-product.The steam is fed directly or on leaving the turbine onto iron heated to about 800.degree. C., which supplies hydrogen and as a by-product ferric oxide. The initial source of energy is, besides solar energy, any known source of energy, such as coal situated at great depths. The starting aqueous substance is, apart from sea water, waste sludges, a rock salt solution or a mixture of sludges and salt solution. In the case of sludges, the by-product is a dry and sterilized fertilizer transformable into fuel bricks. The salt residue is transformable by electrolysis into hydrogen and sodium chlorate, which is a fuel. The sludge-salt residue supplies a combustible mixture.